1. Field of the Invention
The present invention relates to a technique for improving fault tolerance of a computer.
2. Description of Related Art
A fault tolerant computer has been developed in order to provide a high reliable computer. A multiplexing technique is known as a means for improving fault tolerance, which makes a plurality of units having the same function perform the same operation. According to the multiplexing technique, even when a problem arises in any of the plurality of units, a system can be operated without interruption because another unit operates normally.
A computer system is disclosed in Japanese Laid Open Patent Application JP-P2005-165599A. The computer system is provided with an active system on which a program is operating, a redundant system on which the same program is operating in the same execution environment as the active system, and a status saving means for saving a status of the redundant system at a time when fault occurs in the active system.